Tag Archives: 23 cm

ISS Bounce again: now in ISCAT

January 4th, 2015

Jan, PA3FXB, and I were discussing the use of digimodes on ISS bounce for quite a while. Today we tried it with ISCAT-B and were successful with the first shot. As in the tests with Ronald, ON7FLY, on AS, we used 15 seconds periods.

 

From the moment on, traces could be seen in the waterfall diagram, decodes were possible.

2015-01-04 12_14_58-

When the ISS culmiated and the variation of the dopplershift was fastest, the frequency correction came to its limits. But while I am used to ISCAT in the meantime, I needed no decodes to hear, that Jan was transmitting RRRRs.

 

At least I decoded a 73 from him. The experiences with ISCAT in ISS bounce are very promising, although the 15 seconds periods are too long. So we have to discuss it and try with shorter ones.2015-01-04 ISCAT QSO

ISCAT – a new experience

January 3rd, 2015

Inspired by an article, published by Rex, VK7MO, and David, VK3HZ, in the latest DUBUS [1], Ronald, ON7FLY, and I performed a first test in using ISCAT-B mode (by K1JT) for aircraft scatter on 23 cm. When looking on AirScout it doesn´t seem to be very challenging to have an QSO. But Ronald is obstructed by a hill in eastern directions and he didn´t expect to have an opportunity to work eastwards on 23 cm at all.

2014-12-27 16_37_03-AirScout - ON7FLYRonald is located in JO10LT and the distance is just 388 km. He uses a 44 element yagi with only 2 W at the feedpoint. On my side a 3 m dish and 150 W are in use. First of all we tried in SSB and were able to complete a QSO after a while. I could copy ON7FLY very weak, but readable. Then we tried in ISCAT-B with 30 seconds periods and it was amazing to see, that Ronald´s signal could be decoded even when only traces appeared in the spectrum.

2015-01-02 15_28_46-His signal can be seen in the center section (The drop outs are reactions of the AGC on radar noise). The above sequence could be decoded to:

2015-01-02 15_29_22-Since the periods of 30 seconds were far too long, we needed certain airplanes to complete. then we tried FSK441 with no decodes and switched to JT6M and completed the third QSO. In the meantime I found a hint in the above mentioned article, how to reduce the T/R periods to 15 seconds. So we completed a fourth QSO in ISCAT-B again in shortest time: 2015-01-02 18_02_00-

 

[1] Rex Moncur, VK7MO, David Smith, VK3HZ, Aircraft Scatter on 10 and 24 GHz using ISCAT: DUBUS Vol. 43 4/2014

Chaos on 1296.942 MHz!

November 28th, 2014

2014-11-28 10_13_55-OK0el vs DB0AJA

There are good tropo conditions to the east from here for quite a while. I worked OK1MAC on November, 26th with an outstanding signal. OK0EA, SR6LHZ can be monitored constantly. I missed OK0EL on 1296.940, but solved the miracle today. The frequency shifted to .942 and the signal has been covered by DB0AJA. It´s nice to listen, how OK0EL in 526 km distance is battling against nearby DB0AJA,131 km away. As can be seen, DB0AJAs signal is accompanied by several dopplershifted reflections on airplanes.

 

It is interesting to see, that F5LENs refractive index as well as Hepburns tropo index don´t really illustrate the real conditions today. The conclusions is: Always perform a beacon check before switching off! The result may be surprising.

2014-11-29 09-00 F5LEN DJ5AR OK0EL

Presentation “Let´s Bounce” IIa

October 21st, 2014

Last night, when I was going to switch off all the stuff in my shack, I saw an email from Malte, DE7LMS. I opened it and found a link to a video he recorded of my recent presentation in Weinheim.

Presentation “Let´s Bounce” III

My presentation “Let´s Bounce” will be given on two more dates:

October 25th, 2014 on the 4th Hessian GHz Meeting in Fernwald

Short version of the lecture with focus on aircraft scatter and ISS bounce.
We meet at 15:00 MEST on the car park at the town hall. There will be a flee market for GHz stuff and the opportunity to test own equipment or to have QSOs with other participants.

Gaststätte “Ratsschänke”
Oppenröder Strasse 1, 35463 Fernwald-Steinbach
Locator: JO40JN33VG

November 7th, 2014, 20:00 MET on the monthly meeting of DARC OV Miltenberg, B24

Full Version with overview of propagation modes, aircraft scatter, ISS bounce and visual moonbounce.

Deutscher Amateur Radio Club e.V.
Ortsverband Miltenberg, B24
Gasthaus “Goldenes Faß”
Kirchstraße 13, 63920 Großheubach
Locator: JN49OR64JJ

If you like to attend or need further information, just send an email to dj5ar (at) darc.de

IARU-Region-1 UHF/Microwaves Contest 2014

October 5th, 2014

After my complainments about using the ON4KST chat in March Contest and the response I received from Claus, OZ1FDH, and Kjeld, OZ1FF, recommending the KST2ME tool, I added my homebrew prototype of a selective ON4KST client extension to my station control software. It communicates via telnet with the server. While working satisfactorily under normal circumstances, it was a desaster under contest load. When the software didn´t crash, it at least slowed down, by computing hundreds of posts in shortest time. Between 300 and 400 users have been logged to the microwave chat during contest time. During the first contest hours I tried to solve the problems with certain bug fixes, resulting in a huge loss of contest time. So I had to return to the classic style in using the web client of the chat.

QSOs on 23 cm

In total I logged 73 QSOs on 23 cm to 12 DXCC countries, spread over 39 grid squares (results). ODX was HG7F over 817 km. The use of the AirScout software, written by Frank, DL2ALF, has been essential. Most of the QSOs have been completed by assistance of aircraft scatter.

A nice example is the one with DJ5BV in JO30KI. The distance isn´t really far enough to do it via aircraft sctatter, but it seems, both antennas were pointing west and that resulted in effects of aircraft backscatter with significant dopplershifted reflections.

2014-10-05 11_59_34-Backscatter dj5bv innerDopplershifted reflections of Gerd, DJ5BV, caused by backscatter of aircrafts.

 

New 23 cm Beacon DB0XY in JO51EU

September 22nd, 2014

Jürgen, DK2AN phoned me tonight, to tell me, the new beacon DB0XY will be transmitting on 1296.910 MHz. It is located on the Bocksberg in the Harz mountains in JO51EU, about 750 m asl. The power is 10 W into a 4 times double quad, omnidirectional. The keying is in A1: callsign, locator, carrier, dashes, carrier….

In a first quick try it could be received here with 519 to 539 via tropo. When Planes crossed the path, the signal increased up to 559.

Another beacon will be installed on 13 cm soon. The intention is to provide beacons for monitoring via aircraft scatter.

Please spot any reception in the DX cluster.

Presentation “Let´s Bounce”

June 22nd, 2014

On July 24th, 2014 on 19:00 CEST I will talk about how to surmount the horizon on VHF and up at the local DARC Club in Bodenheim near Mainz.

After giving an overview over the classic propagation modes Es, Aurora, MS and Tropo, I will explain, how aircraft scatter and ISS bounce work. EME will be subjected too and the presentation will be completed by an introduction to “Visual Moonbounce” as performed by Daniela de Paulis.

Location:
Deutscher Amateur-Radio-Club e.V.
Ortsverband Bodenheim
Haus der Vereine
Laubenheimer Str. 22
55294 Bodenheim

The admission is free, but please register via email to
DK2FQ   wolfgang.beer (at) gmx.net   or to me   dj5ar (at) darc.de

Article in “Funkamateur” magazine July 2014

June 22nd, 2014

German Funkamateur mgazine has published my article “Abenteuer Bakenbeobachtung von 144 MHz bis 10 GHz” in its recent issue July 2014. As many topics are related to posts on this website, some of them are compiled here. Links to certain other websites can be found in the link list to the right.

Weather, rainscatter:

Rainscatter on 23 and 13 cm
Impressive Thunderstorm

Weather, troposheric ducting:

Another strange constellation (Update)
Strange Conditions
Opening September 21st 2013

Aircraft scatter (video):

PI7ALK via Aircraft Scatter

List of beacons, heard by DJ5AR in Mainz, JN49CV

My new beacon list